Nanocrystalline powder of ferromagnetic spinel CuCr₂Se₄ is synthesized with an average particle size of about 20-50 nm. The nano-powder is characterized using transmission electron microscopy, X-ray diffraction and magnetic measurements. The Curie temperature of the nanocrystals exceeds the value obtained for usual bulk polycrystalline spinel sample. Exposure of the samples by laser radiation at wavelength of 1.5 μm under an external field leads to an increase in magnetization, that is caused by photo and thermo stimulated remagnetization of monodomain nanocrystals.